Current protection devices are used ubiquitously in various modern electrical applications. A common fuse, for example, utilizes a metal wire or strip that melts when exposed to a threshold current. The melting of the metal breaks the continuity of the fuse, which interrupts the circuit in which the fuse is connected. This interruption prevents further damage to electrical components and other structures from overheating and fire.
The use of current protection devices in power electronics applications is especially important, due to the higher susceptibility of overheating parts from exposure to higher currents. Because of this increased risk, regulations oven require current protection. For instance, photovoltaic energy conversion systems for residential, commercial, and industrial applications, must be equipped to detect and interrupt the unintended flow of DC current to ground, known as a ground fault. Detecting whether a fuse has blown in such situations can include measuring a voltage across the fuse. However, voltage measurements across a fuse can be unreliable because voltage can vary with temperature, fuse type, and the nature of a ground fault on a grounded conductor.